Float plug



Aprii 29 1924 1,491,915 W L. M LAINE FLOAT PLUG Filed Sept. 28,

manqu- 2 M m i w W m 5 Patented Apr. 29, 1924.

stares WILLIAM L. MQLAINE, OF LOS ANGELES, CALIFORNIA, ASSIGNOR OF ONE-HALF TO WILLARD L. BUROUGH, OF FULLERTON, CALIFORNIA.

FLOAT PLUG.

Application filed September 28,

To all whom it may concern:

Be it known that I, \VILLIAM L. MCLAINE,

a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and, State of California, have invented a new and useful Float Plug, of which the following is a specification.

My invention relates to the art of drilling oil wells. In that art it is necessary after a well has been drilled to place in the well a string of casing consisting of joints -of pipe secured together by suitable couplings; this casing is often twelve inches or more in diameter and it may consist of several thousand feet of heavy pipe. The strain upon the derrick of the oil well when handling these long strings of casing is considerable and it is an object of my invention to provide means for reducing the strain upon the derrick.

This I accomplish by floating the casing as it is lowered into place in the water or mud with which the hole is filled. For the purpose of making this floating practical, I employ what I have called a float plug which is secured to the bottom of the casing and which is operated as will hereinf after be explained.

Further objects and advantages will be made evident hereinafter.

Referring to the drawing which is for illustrative purposes only,

Fig. 1 is a view of a portion of an oil well with a string of casing being lowered in place therein.

Fig. 2 is a section through a float plug embodying my invention.

Fig. 3 is a section one. reduced scale on a plane represented by the line 3-3 of Fig. 2

In the form of my invention illustrated, I employ a coupling member 11 which is threaded at its upper end to receive the easin 12 and which is threaded at its lower en to receive the body 13. This body is provided with two hubs 14 and 15 carried on arms 16 and 17. Sliding in holes in the hubs 14 and 15 is a stem 21 of a valve 20. The valve is preferably of conical form and is normally seated in an opening in the bottom of the body 13 by means of compression spring 22 acting between the hub 15 and a nut 23 carried on the threaded portion of the stem 21. A spacer 25 resting on the hub 15 inside the spring 22 acts to limit the the casing 12 may be 1922. Serial No. 591,163.

downward movement of the valve 20 by providing an abutment against which the nut 23 strikes after the spring 22 has been partially compressed.

In placing the casing 12 in an oil well 30 32 which rests upon and is supported by any suitable and Well known form of casing elevator 31.

The form of the body 13 makes it especlall suitable for guiding the casing into the ho e as it is rounded off to provide a smooth surface which slides into place without catching on rojections in the hole. The valve 20 being ield against its seat by the spring 22 and the hole 30 being full 0 water, it is evident that advantage can be taken of the buoyancy of the empty pipe which may be diminished by partially filling the casing with water by inserting a hose in its upper end. By using the buoyancy of pipe to float the pipe, the weight that must be carried by the elevator 32 is greatly reduced.

After the casing has reached its lower position it may be cemented in place in the usual manner by forcing cement down through the inside thereof. This cement being driven by a column of water filling the entire interior of the casing above the cement which water is also under some pressure at the surface of the ground due to its being supplied by mud pumps in the usual manner, exerts a pressure upon the valve 20, forcing it downwardly and opening it to allow the cement to pass outwardly and upwardly around the pipe in the usual mansuspended by a collar ner due to the circulation previously estab out after the cement has set.

I claim as my invention 1. In combination, an imperforate string of casing; a body adapted to be secured to and .to entirely close the lower end of said casing so that same may be floated in a well;

and valve means carried in said body' through which cement may be forced from and the members carried of casing; and to entirely close be readily drilled has set.

3. A method of which comprises:

out after said cement placing casing in a well closing the bottom end of the casing with friable material; said casing in the through a valve in placing well; forcing cement 2 the lower end of said casing to securely cement said casing in said well; and thereafter drilling out said friable material.

In testimony whereof, I

at Los Angeles,

set my hand this 21st day of Se WIL 'srsecam l,49l,9.l5.vW'illiam L.

- April 29, 1924.

McLaine, Willard Tools, Inc, exclusive licensee.

close the lower end bore.

Your petitioners of said patent, namely, claim 3, which is in 3. A d of pl through a valve in the lower end of sand well; and thereafter drilling [aficlal Gazette'April 17; 1934,]

McLainegLos Angeles, Calif. FL

Disclaimer filed Mar L. Burough, assign also hereby disclaim that which comprises g l the DAT PLUG. ch 26, 1934,, by th cc of one-half interest, and Baker part of the claim the following words, acing casing in a well end of the caslng with friable material placing said cas have hereunto 25 California. tember, 1922. v EIAM L. MoLAINE.

Patent dated e patentee, said in the specification to wit:

: closing the bottom well; forcing cement casing to securely cement said, casing 'insaid out sa d friable matenal. 

